1. Field of the Invention
The present invention relates to an energy-saving device, and more particularly to a feedwater heater with a recovery device for swelling water.
2. Description of the Prior Art
FIG. 1 is a schematic view showing the system arrangement of a conventional feedwater heater. The feedwater heater has a heating container 1. The heating container 1 is connected with a water inlet pipe 2 and a water outlet pipe 3. The water inlet pipe 2 is connected to a water outlet valve 5 of a faucet 4. The water outlet pipe 3 is connected to a water outlet 6 of the faucet 4. When the water outlet valve 5 is opened by the user, the cold water in the water inlet pipe 2 will flow into the heating container 1 to be heated by the heating container 1. Afterward, the hot water flows out through the water outlet pipe 3 for use.
However, when the water outlet valve 5 is closed by the user, the hot water and the steam in the heating container 1 will rise due to the principle of thermal expansion as well as rising of hot air, which causes the water outlet 6 of the faucet 4 to drip water easily. Besides, the hot energy in the heating container 1 may lose. When the user wants to get hot water next time, the heating container 1 will carry out the heating operation again. This consumes energy very much and is not environmental-friendly. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.